import 'dart:io';

 main(List<String> args) async {
 print("main start");
 
getNetworkData().then((value) => print(value));


 print("main end"); 
}


Future getNetworkData() async{
  String res = await Future((){
  sleep(Duration(seconds: 3));
  return "hello world";
  });
  return res + "123";
}


